My 37 D5 came with an LT1 and 6 speed trans already installed. Not my choice of power plant but it is what it is.

I just picked up a well running slant 6/904 combo which was plucked from a 67 Coronet for free! (well a bottle of rum actually. Love the barter system) Also got the driveshaft and rear end as well thrown in!

The LTI actually fits pretty well in the coupe, but I wanna prep the slant 6/904 to eventually install it in place of the chev stuff.

This is my first exposure to the slant 6. Will there be any fitment issues that I should be aware of. Haven't really sized the /6 up very well yet, as it is still sitting in the back of my truck while I am working 350 km offshore. JUST picked it up. The front of the car is fairly narrow as you know, but like I said the LT1 fits in there pretty good. I'm wondering if the sheet metal is wide enough to accommodate the "lean" of the /6.

I know that a small block might be more practical, but I'm just wanting something simple and different that fits well and is dead nuts reliable in the long run. And the price was certainly right. Not looking for a ton of power either. Not a priority anymore.

I believe the slant 6 is a little longer then the original flathead was, and the firewall was inset to accommodate the flathead's length. Likely the slant 6 won't fit into the recess for the flathead because of the angle, but none of that may matter at all. We have no idea what was done to put the LT1 in the car. In addition, I have no idea how the length of the slant 6 compares to the length of the LT1, they may be the same length, but odds are better the slant 6 is longer then the V8.I would guess it depends on if or how much the 37's firewall has been modified to fit in the Chevy V8.

the engine bay difference between a 34 and a 37 is virtually zero. the body differences are another story.figure on at least some firewall mods and of course, the engine wiring harness. if the GM engine has an electric fan, you may want to consider keeping that.good luck on your project. keep us updated on the progress, please.

The firewall appears to be stock. It does have an electric cooling fan, which is a pusher so that will help with room fore and aft. As for the wiring harness, it has enough of the 95 Camaro harness to make the fuel injection work (ECM and sensors), but the starting and charging system is all tied into the universal aftermarket harness.

i owned a 38 coupe, and my one buddy owned a 37 sedan, plus, i parted out several 37/38 sedans. the firewall is indeed, stock on your car. when the time comes for the mockup of the /6, consider replacing the pusher fan with a factory [OEM] style puller. since the 6 lays over, you may find by ditching the fixed fan and spacer, the firewall mods may be minimal, and the puller fan can be mounted high, missing the engine. as i don't have a /6 here to measure, i can't tell you the length.although the original engine was a 6 as well, it may, or may not, be close. i'm saying this because the inline 6 was a heavy type of casting, while the /6 was a lighter, more "modern" style of casting, and may be very close to the original in size.it was designed to fit in the new A body, and those had not only a lower hood line, but a somewhat cramped engine bay as well.in the very early 70's, my one buddy had a T-bucket with a slant, and that thing would flat out scoot ! i realize that is an apples to kumquat comparison, but the cool factor was way high.

Not that much of a GM guy but my understanding is that the LS is sever so lightly smaller in most respects than the SBC. But that really depends on what is dressing what.

Tunnel ram on a 350, it'll be taller, but stock intake vs stock intake the LS can be taller. No distributor on the LS so firewall clearance is better on an LS. Exhaust ports sit higher on an LS, so header clearances can be different. Oil pan choices are slimmer on an LS and not as easily cut and welded to clear. Not really a clear answer for you.

i know engine height can vary a ton between installations, but the E58 360 i had in my coupe would have had no issues with running a tunnel ram under the stock hood with no modifications. it would have been CLOSE, but doable.as i used a reversed corvair box on mine, i used a pair of 69/69 passenger side [center dump] manifolds from a 340 dart. owning a junkyard back then helped with parts. center dump headers were not available back then.

Thanks for all of the replies guys. I'll use what's under the hood for now to see how it runs. It was in the car when I got it. Haven't really driven it yet, only around the yard. No interior. That's what I'm working on now.

Out of curiosity, does a /6 and a small block share the same trans mounting bolt pattern? May have a lead on a cheap rebuilt 318 as well.

No on the bell housing pattern, for the most part. There is a bell the 60's trucks used that incorporated the rear motor mounts that had both patterns. It was for the NP435 truck 4 speed (granny first).

I also have a very vague recollection of a factory adapter plate that allowed the SB bell on a /6 in 60's vans.

They say there are no such thing as a stupid question.They say there is always the exception that proves the rule.Don't be the exception.

in my junkyard ownership days, we had a 68, 3/4t pickup yard truck that was /6 - 727 powered with the dash mounted shifter.it had the adapter plate for the small block pattern 727. it was the only /6-727 combo we ever got in. all the other truck/van automatics with the 6 were 904's. and we took in a bunch of 'em.

Every time I start looking or asking about stuff like this, I always feel that I was born 10-15 years too late. Might be different in the warmer climates where some vintage iron can still be found in the wrecking yards, but here in the north east it's all newer crap. I would have loved to own/work in a scrap yard back in the day, knowing what we know now.

the slant six bellhousing is its own pattern---if i lived in europe i would be tossing a 5 cylinder mercedes diesel in that and driving the hell out of it----in the 50,s the big dodges and desotos got sent to europe as taxis and they were fitted with small diesels-----by a diesel plant owned by chrysler then sold to cummins.....